/**
 * @license Copyright (c) 2003-2023, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */
/**
 * The block indentation behavior that uses offsets to set indentation.
 */
export default class IndentUsingOffset {
    /**
     * Creates an instance of the indentation behavior.
     *
     * @param config.direction The direction of indentation.
     * @param config.offset The offset of the next indentation step.
     * @param config.unit Indentation unit.
     */
    constructor(config) {
        this.isForward = config.direction === 'forward';
        this.offset = config.offset;
        this.unit = config.unit;
    }
    /**
     * @inheritDoc
     */
    checkEnabled(indentAttributeValue) {
        const currentOffset = parseFloat(indentAttributeValue || '0');
        // The command is always enabled for forward indentation.
        return this.isForward || currentOffset > 0;
    }
    /**
     * @inheritDoc
     */
    getNextIndent(indentAttributeValue) {
        const currentOffset = parseFloat(indentAttributeValue || '0');
        const isSameUnit = !indentAttributeValue || indentAttributeValue.endsWith(this.unit);
        if (!isSameUnit) {
            return this.isForward ? this.offset + this.unit : undefined;
        }
        const nextOffset = this.isForward ? this.offset : -this.offset;
        const offsetToSet = currentOffset + nextOffset;
        return offsetToSet > 0 ? offsetToSet + this.unit : undefined;
    }
}
